The present invention relates to a vending machine that contains an array of capacitive switches to determine the height and/or inventory of products contained in the racks inside the vending machine.
Vending machines contain goods, products and/or services that are vended to customers. One type of common vending machine is a beverage vending machine that vends beverages contained in aluminum cans.
Vending machines contain racks that store the products to be vended. The racks are vertical storage areas in which the products are stacked on top of each other. When a product is selected, the rack releases the product contained in the bottom of the rack, and the products stacked onto top of the bottom product move down one position. The products in the rack continue to move down in position until the last product in the rack is vended. Service personnel refill the racks with products periodically to preferably keep the racks from being totally emptied.
Racks in the vending machine contain products of the same type so that a product selection by a customer corresponds to a particular rack that contains the type of product selected. For example, a vending machine that has five beverage selections contains at least five different racks; one for each beverage selection. Some vending machines contain more racks than product selections. If a particular product is vended more often than others, the more popular product may be contained in more than one rack so that the vending machine does not run out of the popular product faster than other products.
Most vending machines are not capable of detecting the actual inventory count of products in its racks. The vending machine may be capable of counting the number of vended products, but there is no guarantee that a service person filled up the rack completely at the last fill up. Some vending machines may also not have knowledge of their maximum capacity so that the number of vended products can be subtracted from the maximum capacity to determine the actual inventory of products remaining in a given rack.
Some vending machines may contain an array of switches that are aligned with products and are capable of detecting the height of products remaining in a given rack. The height of the products can be correlated to the actual number of products in the rack if the products each have uniform height. For example, U.S. Pat. No. 4,398,651 to Kumpfer et al. entitled xe2x80x9cMicrowave food dispensing machinexe2x80x9d discloses a food vending machine that contains an array of magnetic reed switches to detect the height of remaining products. However, magnetic reed switches may not work properly in a vending machine that contains a cooled environment, such as a cold beverage vending machine, due to condensation occurring around the switches. Other types of switches, such as weight sensors, are not practical due to the fact that a weight sensor would have to be placed on a moveable rack release arm.
Therefore, a need exists to provide an array of switches aligned with products in a vending machine rack to detect the height and/or inventory of the products that is not susceptible to condensation caused by a cooled environment and/or does not have to be attached to the moveable rack release arm.
The present invention relates to a vending machine that contains racks with stacked products for vending to consumers. An array of capacitive switches is aligned with the racks containing the vended products. The array of capacitive switches are coupled to a control system that is capable of determining if a vended product is present at a particular location in the rack. In one embodiment, the array of capacitive switches is comprised of a plurality of capacitive switches.
The control system is capable of determining the height of the products in the rack using the array of capacitive switches. Since the products are typically of a uniform individual height and there are no space gaps between stacked products, the total number of products in a given rack can be derived from the height of highest product contained in the rack.
The control system is adapted to communicate the height and/or inventory of products in the rack to an outside communication device, such as a hand-held device and/or a remote site. The communication link between the control system and the outside communication device may be a wired or wireless connection.